Breast Cancer Research and Treatment 83: 201–210, 2004. © 2004 Kluwer Academic Publishers. Printed in the Netherlands. Report Energy balance in early breast cancer patients receiving adjuvant chemotherapy Michelle N. Harvie 1 , I.T. Campbell 2 , A. Baildam 3 , and A. Howell 1 1 University Department of Medical Oncology, 2 University Department of Anaesthesia, 3 University Department of Surgery, South Manchester University Hospitals NHS Trust, Manchester, UK Key words: adjuvant chemotherapy, breast cancer, central fat, resting energy expenditure, weight gain Summary Weight gain is a common problem amongst women receiving adjuvant chemotherapyfor early breast cancer. We undertook a study to determine the causes of this weight gain. Prospective measurements of body mass and compo- sition (skinfolds, bioelectrical impedance, total body potassium), energy balance (resting energy expenditure dietary intake, and physical activity), were determined in 17 women during and in the 6 months after com- mencing adjuvant chemotherapy. Women gained significant amounts of weight (5.0 ± 3.8; p< 0.01) and body fat (7.1 kg ± 4.5; p< 0.01) over the year. Waist circumference (5.1 ± 4.5 cm; p< 0.01) and abdominal skinfold (16.2 ± 10 mm; p< 0.01) were also increased but there was a decline in fat free mass (FFM); 1.7 ± 2.5 kg. Women due to receive adjuvant chemotherapy had a greater resting energy expenditure (REE) compared with healthy sub- jects (n = 21); 100.5 ± 8.0% Harris Benedict compared to 94.5 ± 8.4% Harris Benedict (p = 0.05). REE declined by 3% during adjuvant chemotherapy (p< 0.05), and remained depressed until at least 3 months posttreatment. There were no significant changes in dietary intake or physical activity over the year. Failure of women to reduce their energy intake to compensate for the decreased energy requirement may account for some of the weight gain. Treatment of adjuvant chemotherapy causes gain of body fat because of reduced energy expenditure, and the failure of women to reduce their energy intake to compensate for the decline in energy requirement during and in the 6 months posttreatment. Since weight gain impacts on survival, patients should be counselled to reduce energy intake and exercise during and after adjuvant treatment. Introduction Weight gain is a well-established side effect amongst women receiving adjuvant chemotherapy, which is as- sociated with reduced survival [1, 2]. Generally weight gain is due to an imbalance of energy intake and energy expenditure but the reasons for the positive en- ergy balance during and after adjuvant chemotherapy have not been firmly established. Three recent studies [3–5] measured components of energy balance (body weight, food intake and rest- ing energy expenditure) during chemotherapy for early breast cancer but the findings were inconsistent. Over the course of chemotherapy REE was reported to be increased [4], decreased [3] or unchanged [5]. Energy intake was reported to be decreased [3] or unchanged [4, 5] while physical activity was unchanged [4] or decreased [3, 5]. Interpretation of these studies is limited by the fact that patients did not put on the previously reported large amounts of weight, raising the possibility that intense metabolic monitoring dur- ing the studies may have affected normal behaviour and limited weight gain. Since gain also occurs in the 6 months after completion of chemotherapy, there is also a need to study energy balance in this period as well as during treatment. In order to determine the reasons for weight gain we studied changes in body composition and energy balance (REE, physical activity, energy in- take) during chemotherapy, and in the 6 months after chemotherapy, in patients receiving adjuvant treatment. A parallel group of controls about to